|
Turbo C 2.0、Borland C++库函数及用例(30) 功 能: 向下舍入
用 法: double floor(double x);
程序例:#include <stdio.h>
#include <math.h>int main(void)
{
double number = 123.54;
double down, up; down = floor(number); up = ceil(number); printf("original number %10.2lf\n",
number);
printf("number rounded down %10.2lf\n",
down);
printf("number rounded up %10.2lf\n",
up); return 0;
}
函数名: flushall
功 能: 清除所有缓冲区
用 法: int flushall(void);
程序例:#include <stdio.h>int main(void)
{
FILE *stream; /* create a file */
stream = fopen("DUMMY.FIL", "w");
/* flush all open streams */ printf("%d streams were flushed.\n",
flushall());
/* close the file */
fclose(stream);
return 0;
}
函数名: fmod
功 能: 计算x对y的模, 即x/y的余数
用 法: double fmod(double x, double y);
程序例:#include <stdio.h>
#include <math.h>int main(void)
{
double x = 5.0, y = 2.0;
double result; result = fmod(x,y); printf("The remainder of (%lf / %lf) is \
%lf\n", x, y, result);
return 0;
}
函数名: fnmerge
功 能: 建立新文件名
用 法: void fnerge(char *path, char *drive, char *dir);
程序例:#include <string.h>
#include <stdio.h>
#include <dir.h>int main(void)
{
char s[MAXPATH];
char drive[MAXDRIVE];
char dir[MAXDIR]; char file[MAXFILE];
char ext[MAXEXT]; getcwd(s,MAXPATH); /*get the current working directory*/
strcat(s,"\\"); /*append on a trailing character*/
fnsplit(s,drive,dir,file,ext);
/* split the string to separate elems */
strcpy(file,"DATA");
strcpy(ext,".TXT");
fnmerge(s,drive,dir,file,ext);
/* merge everything into one string */
puts(s); /* display resulting string */
return 0;
}
函数名: fopen
功 能: 打开一个流
用 法: FILE *fopen(char *filename, char *type);
程序例:#include <stdlib.h>
#include <stdio.h>
#include <dir.h>int main(void)
{
char *s;
char drive[MAXDRIVE];
char dir[MAXDIR]; char file[MAXFILE];
char ext[MAXEXT];
int flags; s=getenv("COMSPEC");
|
